Entanglement plays a central role in many fields of physics, including many body systems, quantum information, and quantum field theories. In the context of AdS/CFT, Ryu and Takayanagi proposed that the holographic dual of the entanglement entropy is captured by the area of a minimal co-dimension two surface in the bulk. Large amount of evidence have accumulated and an explanation as the generalized gravitational entropy was made by Lewkowycz and Maldacena.　

　

On the other hand, the success of holography goes beyond AdS/CFT, for instance, the recent development of the Kerr/CFT correspondence, flat space holography, Shrodinger or Lifshitz spacetime/non-relativistic field theory duality, etc. One of the simplest examples is the so-called Warped AdS3 (WAdS3) spacetime, whose holographic dual has been conjectured in the literature.　　

 

In this talk, I will report some progress on deriving the holographic entanglement entropy for spacetimes which are not asymptotic to AdS. We propose an adaption to the Lewkowycz-Maldaceda procedure. Explicit calculation is carried out for WAdS3 in a simple theory. It turns out that the entanglement entropy in WAdS3 is captured by the least action of a charged particle in WAdS3 space, or equivalently, by the geodesic length in an auxiliary AdS3. Consequently, the bulk calculation agrees with the CFT results, providing another piece of evidence for the WAdS3/CFT2 correspondence.